Monday, October 17, 2011

Tractor travails

I've been having problems with my big orange tractor for the last 2 or 3 weeks. It would work fine for a random period of time, and then stop. Since there are multiple people using the tractor, and it seemed to be out of fuel each time this happened, I chalked it up to operator error -- the guy driving the tractor not watching the fuel gauge.

The problem with that is that a diesel engine out of fuel is not as simple as a gas engine is when you go to restart it. So I trained all of the people on the farm to restart a fuel-out situation, but we kept having problems.

So I'm working on this problem, and I fill the fuel tank to the brim. I get the service manual, and I"m working through the steps to restart the engine, and I end up doing this 6 times, because the book says that if the engine does not start to repeat the steps. Each time I can get 10-15 minutes of work out of it before the engine dies.

This is really frustrating. The maintenance manual has the fuel priming sequence starting from the fuel filter forward, and so I started replacing the fuel filters, figuring that maybe the fuel had something in it causing this problem or blockage. Same behavior. 10 minutes and then it dies.

So I read the maintenance manual, and they talk about a fuel solenoid that is only open when powered, so I figure out a way to get a voltmeter in there, and it is powered, and the power doesn't flicker, so that's not the problem.

So after 8 days of this, I'm staring at the tractor, and finally start looking at the diesel fuel tank in suspicion. I disconnect the fuel line from the tank, and see if I can suck some diesel out. I cannot. So I try blowing into the tank; and it will accept air -- and suddenly the fuel starts to flow out the tube.

That's very weird. Ok, I'm going with it. maybe it's the tanks. So a jury-rigged 5 gallon diesel jug and a bit of copper tubing, and... no more problems. No problems for days. As long as I don't run off the tractor tanks it all works. Weird.

So off come the diesel tanks. Maybe it's algae, or... I don't know what. The picture below is what was found in the tanks.

It's a latex glove. it's been in there a while. So this darned thing was floating around in the tank, and would get caught in the fuel intake hose now and then. So blowing into the tank just got it off the tub, and allowed fuel to flow. When it was covering the tube, the engine would die.

We don't use these gloves at our farm at all, and the once-white glove is pretty discolored. I'm guessing that this is a factory-original glove that floated around in the tank. Mystery solved, problem solved.

My smaller tractor has had some flexing going on in the front end, and it caused the fan belt to wear a hole in the radiator tub. After fixing the rear bracket I was using the little guy to spread lime and noticed that the front loader was doing odd things. It was moving when it shouldn't. Closer inspection showed the frame of the tractor had broken. A quick look on the other side showed a similar break. Calling the tractor dealer got me a quote on the price for this part: $1300 and a week or 10 days for the part to get here. And labor costs and a few days to take it out and put it back in, for a total of maybe $1800 at shop rates.

For $1800 I don't think I'm going to replacing this part. I'll have it taken out and welded and then put the thing back together; I think I can get that done in a few days, and hopefully for less than $400.

The break on the small tractor isn't new; there's rust on the edges. What I think was happening is that over time the bolts that were holding things together snapped off, and as they did the fit got looser and looser.

I use the tractors a lot on the farm; having one out is a headache, but having both out is a big deal.

I'm hoping that the small tractor comes back in time to take the load from the big tractor, which needs to have a new clutch put in.

5 comments:

Jerry Plummer
said...

Your problems with the tractor made me think of my brother in law flying over Anchorage when the engine of his small plane stopped. He made an emergency landing in a school yard. On inspection they found in the tank the funnel to a five gallon gas can which was the perfect size to exactly fit in the gas intake pipe. Same kind of situation--a previously owned plane. Who knows how long that part had been floating around in there.

I enjoy your blog very much. You post great pictures, and explain your thinking in a very interesting way. Thanks for doing this.

How old is the tractor? I'm curious how long that glove had been in there.

I had a problem with the fuel in my old Renault at one point, but we use Claude the Manic Mechanic who is some old boy retired Renault mechanic who wanders by at call to help out if I break something. He talks at a million miles an hour in a huge Gascon accent.

In a few of minutes he'd gone through the entire fuel system (including the tank flow as you describe above) and found a secondary filter that was full of decayed rubber o-ring. He's fast, cheap and out of control.

thank you Jerry. I wonder sometimes when I write about the day to day stuff, if it's interesting. My early life was spent as an software engineer, and you spend a lot of time trying to figure out why things go wrong there, too. This tractor fuel problem seemed like the same sort of exercise. I am very glad to have that glove out of that tank. It was driving me nuts.

one nice thing abou a tractor is you don't have to worry about falling out of the sky!

bc, it's a 1996 Kubota 9580. when I got it the hour meter read 971, and after I used it for a week the hour meter read 971. I replaced the hour meter and I've put 600 hours on that tractor in 2 years.

The tank cleanout and welding job I've given to Doug, who is Seans' father -- Sean is one of my farmhands. I'm interested to see how this welding thing goes. On my farm, someone who can do a decent job welding is pretty valuable.